Foundation pit excavation auxiliary dewatering device and method

Abstract

The application discloses a kind of foundation pit excavation auxiliary precipitation device and method, it is related to earthwork excavation technical field, wherein, the foundation pit excavation auxiliary precipitation device includes the mounting bracket fixed to foundation pit slope, the support frame that is obliquely hinged to mounting bracket and bottom end abuts to the soil body to be dug, vertically extending rotary digging mechanism and the precipitation mechanism installed to support frame.The application can integrate rotary digging well, mud real-time filtration, groundwater cavity pumping and temporary drainage well depth dynamic following in the same vertical operation stroke on the basis of primary precipitation of primary pipe well, without a large number of additional fixed pipe well in foundation pit, it can be dug and lowered with digging, effectively reduce the risk of foundation pit bottom plate sudden gushing damage, shorten auxiliary precipitation operation cycle, reduce equipment occupied site and repeated adjustment process.

Description

Technical Field

[0001] This invention relates to the field of earthwork excavation technology, and in particular to an auxiliary dewatering device and method for foundation pit excavation. Background Technology

[0002] Currently, in the construction of ultra-large and ultra-deep foundation pits, when there is a high pressure head at the bottom that may cause sudden heave damage to the foundation pit floor, or when there are multiple aquifers with complex hydraulic connections between them, primary wells often cannot lower the groundwater level of all layers to a safe elevation. In such cases, the conventional approach is to add secondary wells within the foundation pit to further lower the local deep groundwater level through well pumping. While this method can meet the dewatering requirements, it requires a large number of wells to be installed within the foundation pit, occupying construction space, increasing the number of well-drilling procedures, and requiring repeated relocation of the wells during the excavation process, which seriously affects the construction progress and also increases the design difficulty of the foundation pit support structure.

[0003] However, the existing secondary well dewatering method has the following obvious shortcomings: First, the well construction cycle is long and the construction interference is large. Especially in ultra-deep foundation pits and areas with large-area local deepening, adding a large number of secondary wells will significantly extend the construction period. Second, the well layout is fixed and it is difficult to adjust synchronously with the excavation face. This can easily lead to dewatering lagging behind excavation, resulting in excessively high local water pressure and potential safety hazards from sudden surges. Third, the equipment investment and operating costs are high, and the overall construction efficiency is low, which is far from meeting the current construction requirements of "fast, safe and economical" for ultra-large and ultra-deep foundation pits. Summary of the Invention

[0004] The main objective of this invention is to propose an auxiliary dewatering device and method for foundation pit excavation, which aims to solve the problems of long well completion cycle, lag behind excavation, and high risk of sudden water inrush in existing secondary well dewatering systems.

[0005] To achieve the above objectives, the present invention proposes an auxiliary dewatering device for foundation pit excavation, used for auxiliary dewatering of local deep confined water or complex aquifers within the foundation pit, based on the initial dewatering through primary wells. The auxiliary dewatering device comprises: Mounting frame, which is fixed to the slope of the foundation pit; The support frame is inclined vertically towards the slope, the top of the support frame is hinged to the end of the mounting frame away from the slope, and the bottom of the support frame abuts against the soil to be excavated in the foundation pit. A rotary drilling mechanism includes a lifting drive unit, a connecting assembly, a filtering unit, and a rotary drilling unit. The lifting drive unit is hinged to the end of the mounting frame away from the slope. The connecting assembly extends vertically and its upper end is fixedly connected to the lifting end of the lifting drive unit. The filtering unit is fixedly connected to the connecting assembly so that it moves vertically with the connecting assembly without rotating. The rotary drilling unit includes a rotary drilling drive component and a cutterhead assembly. The rotary drilling drive component is installed at the lower end of the connecting assembly. The cutterhead assembly is located below the filtering unit and is vertically spaced by a predetermined distance from the filtering unit. The rotary drilling drive component drives the cutterhead assembly to rotate around a vertical axis. The precipitation mechanism includes a first pump body, a second pump body, a first hose reel, a second hose reel, a mud suction hose, and a groundwater suction hose. The first pump body and the second pump body are fixedly mounted on a support frame. The first hose reel and the second hose reel are rotatably mounted on the support frame. The mud suction hose is wound around the first hose reel, with its inlet end extending into the filter section and its outlet end connected to the inlet end of the first pump body. The groundwater suction hose is wound around the second hose reel, with its inlet end extending into the filter section and its outlet end connected to the inlet end of the second pump body. The filter section includes a first filter ring and a second filter ring arranged coaxially. The first filter ring is sleeved outside the second filter ring, and a mud suction chamber is formed between the first filter ring and the second filter ring. A groundwater suction chamber is formed on the inner circumference of the second filter ring. The mud suction chamber and the groundwater suction chamber are connected through the second filter ring. The inlet end of the mud suction hose is engaged with a first limiting hole on a first ear plate on the inner wall of the first filter ring, and the inlet end of the groundwater suction hose is engaged with a second limiting hole on a second ear plate on the inner wall of the second filter ring. Both the first limiting hole and the second limiting hole extend vertically so that the two inlet ends move vertically synchronously with the filter section. The lifting drive unit drives the connecting assembly to move vertically up and down, so that the filtering unit and the rotary drilling unit move up and down synchronously. The cutterhead assembly directly drills in the soil to be excavated to form a temporary drainage well without a well wall pipe. The filtering unit moves down synchronously with the rotary drilling unit. During the rotary drilling process, the mud entering the temporary drainage well is filtered in stages by the first filter ring and the second filter ring, allowing groundwater to pass through the second filter ring and enter the groundwater suction chamber. The first pump body is used to pump out the mud in the mud suction chamber through the mud suction hose, and the second pump body is used to pump out the groundwater in the groundwater suction chamber through the groundwater suction hose. Furthermore, during the excavation of the foundation pit, the stroke of the lifting drive unit is adjusted synchronously according to the descent depth of the excavation face, so that the rotary drilling unit always stays ahead of the current excavation face by a preset depth, maintaining the effective dewatering depth of the temporary drainage well.

[0006] The technical solution of this invention achieves the following beneficial effects by employing the following techniques: fixing the mounting frame and inclined support frame to the slope of the foundation pit to form a stable working platform; fixing the filter part to a vertically extending connecting assembly so that the filter part moves vertically up and down synchronously with the connecting assembly without rotating; driving the cutter head assembly to rotate around the vertical axis by a rotary drilling drive to directly rotary drill in the soil to be excavated to form a temporary drainage well without a well wall pipe; utilizing the first and second filter rings to form a double-layer coaxial filtration structure for mud suction chamber and groundwater suction chamber; setting the first and second rotary cutting protrusions to work together to complete cutting and crushing; and using the first ear plate, the second ear plate, and the vertically extending limiting hole to make the liquid inlet end of the dewatering mechanism move synchronously with the filter part; and using the rotation of the first and second hose reels to retract and extend the hose. First, this invention integrates direct rotary drilling, real-time mud filtration, underground water cavity pumping, and dynamic depth tracking of temporary drainage wells into the same vertical working stroke. The cutterhead assembly directly rotary drills in the soil to be excavated to form a temporary drainage well without a well wall pipe, eliminating the traditional step-by-step operation mode of installing a well wall pipe and pumping water after the well is completed, thus significantly shortening the auxiliary dewatering operation cycle and improving construction efficiency.

[0007] Secondly, since the rotary drilling unit is always synchronously adjusted according to the descent depth of the excavation face through the lifting drive unit, it can continuously maintain a depth ahead of the current excavation face preset depth, so that the dewatering depth of the temporary drainage well can be dynamically maintained during the excavation process of the foundation pit. This avoids the problem of dewatering lag caused by the fixed position of the well and the difficulty in adjusting it with the excavation face in the prior art, and effectively reduces the risk of sudden surge damage to the foundation pit bottom plate.

[0008] Furthermore, this invention significantly reduces the risk of mud particles clogging the suction channel through the real-time crushing effect of the second rotary cutting protrusion and the graded filtration structure formed by the first and second filter rings. Simultaneously, the design of the first and second ear plates, with their vertically extending first and second limiting holes, allows the inlet ends of the mud suction hose and groundwater suction hose to move synchronously downwards with the filter assembly. The first and second pump bodies can be fixedly installed on the support frame, eliminating the need for movement with the rotary drilling mechanism, thus reducing the frequency of equipment adjustments and maintenance and lowering operating costs. Moreover, because the filter section does not rotate but only moves vertically with the connecting assembly, the inlet ends of the mud suction hose and groundwater suction hose do not rotate circumferentially. The two hoses do not accumulate torsional stress throughout the operation, eliminating the need for a rotary joint and preventing entanglement and damage, further improving the reliability of continuous suction operations.

[0009] Finally, this invention only requires a small number of devices to be installed on the slope of the foundation pit to achieve targeted auxiliary dewatering of local deep confined water or complex aquifers, without the need to arrange fixed wells over a large area in the foundation pit, thus reducing the occupation of the construction site in the foundation pit and also reducing the adverse effects of a large number of wells on the design of the foundation pit support structure.

[0010] In summary, this invention addresses the technical problems of primary wells in ultra-large and ultra-deep foundation pits being unable to meet deep dewatering requirements, and traditional secondary wells having long well-construction cycles, being prone to clogging, lagging behind excavation, and being costly. It provides an auxiliary dewatering technology solution that can dewater as it is excavated, has unobstructed filtration, controllable depth, and is economical and efficient, thus better meeting the current construction needs of deep foundation pit projects for speed, safety, and economy. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of an embodiment of the foundation pit excavation auxiliary dewatering device provided by the present invention. Figure 2 This is a schematic diagram of a structure of an embodiment of the precipitation mechanism involved in the present invention; Figure 3 This is a schematic diagram of a structure of an embodiment of the rotary drilling mechanism involved in the present invention; Figure 4 This is a schematic diagram of the structure of an embodiment of the filter section involved in the present invention; Figure 5This is a schematic diagram of a structural embodiment of the rotary drilling unit involved in the present invention; Figure 6 This is a schematic diagram of the installation structure of an embodiment of the mud suction hose and groundwater suction hose involved in the present invention; Figure 7 This is a flowchart illustrating an embodiment of the foundation pit excavation auxiliary dewatering method provided by the present invention.

[0013] Explanation of icon numbers: 10. Soil to be excavated; 20. Slope; 30. Temporary drainage well; 100. Mounting frame; 200. Support frame; 300. Rotary drilling mechanism; 400. Dewatering mechanism; 500. First ear plate; 600. Second ear plate; 310. Lifting drive unit; 320. Connecting assembly; 330. Filter unit; 340. Rotary drilling unit; 321. Connector; 322. Annular cage; 331. Mounting base plate; 332. First filter ring; 333. Second filter ring; 301. Mud suction chamber; 302. Groundwater pumping unit Suction chamber; 341, rotary drilling drive component; 342, cutterhead assembly; 343, cutterhead body; 344, first rotary cutting protrusion; 345, connecting shaft; 346, second rotary cutting protrusion; 410, first pump body; 420, second pump body; 430, first hose reel; 440, second hose reel; 450, mounting rod; 460, mud suction hose; 470, groundwater suction hose; 501, first limiting hole; 601, second limiting hole.

[0014] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0017] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0018] Please see Figures 1 to 6In one embodiment of the present invention, a primary manhole has been installed and preliminary dewatering has been completed before the foundation pit is excavated. The foundation pit includes a slope 20 and soil to be excavated 10. The primary manhole is an existing primary dewatering facility around the foundation pit. This device does not change its structure, but only supplements the dewatering of local deep confined water or complex aquifers on the basis of the preliminary dewatering of the primary manhole. This foundation pit excavation auxiliary dewatering device is used to perform auxiliary dewatering of local deep confined water or complex aquifers in the foundation pit on the basis of the preliminary dewatering of the primary manhole. It includes an installation frame 100, a support frame 200, a rotary drilling mechanism 300, and a dewatering mechanism 400. The mounting frame 100 is fixed to the slope 20 of the foundation pit; the support frame 200 is vertically inclined towards the slope 20, the top of the support frame 200 is hinged to the end of the mounting frame 100 away from the slope 20, and the bottom of the support frame 200 abuts against the excavated soil 10 of the foundation pit; the rotary drilling mechanism 300 includes a lifting drive component, a connecting assembly 320, a filter part 330, and a rotary drilling part 340, the lifting drive component forms a lifting drive part 310, the lifting drive part 310 is hinged to the end of the mounting frame 100 away from the slope 20, the connecting assembly 320 extends vertically, and the connecting assembly 320... The upper end is fixedly connected to the lifting end of the lifting drive unit 310, and the filter unit 330 is fixedly connected to the connecting assembly 320 so that it moves vertically with the connecting assembly 320 without rotating. The rotary drilling unit 340 includes a rotary drilling drive 341 and a cutter head assembly 342. The rotary drilling drive 341 is installed at the lower end of the connecting assembly 320, and the cutter head assembly 342 is located below the filter unit 330 and is vertically spaced by a preset distance from the filter unit 330. The rotary drilling drive 341 is used to drive the cutter head assembly 342 to rotate around the vertical axis. The dewatering mechanism 400 includes a first pump body 410 and a second pump body 420. A first hose reel 430, a second hose reel 440, a mud suction hose 460, and a groundwater suction hose 470 are mounted on a support frame 200. A first pump body 410 and a second pump body 420 are fixedly mounted on a support frame 200. The first hose reel 430 and the second hose reel 440 are rotatably mounted on the support frame 200. The mud suction hose 460 is wound around the first hose reel 430. The inlet end of the mud suction hose 460 extends into the filter section 330, and the outlet end of the mud suction hose 460 is connected to the inlet end of the first pump body 410. The groundwater suction hose 470 is wound around the second hose reel. 440, the inlet end of the groundwater suction hose 470 extends into the filter section 330, and the outlet end of the groundwater suction hose 470 is connected to the inlet end of the second pump body 420; the filter section 330 includes a first filter ring 332 and a second filter ring 333 arranged coaxially, the first filter ring 332 is sleeved on the outside of the second filter ring 333, a mud suction chamber 301 is formed between the first filter ring 332 and the second filter ring 333, and a groundwater suction chamber 302 is formed on the inner circumference of the second filter ring 333, and the mud suction chamber 301 and the groundwater suction chamber 302 are connected through the second filter ring 333;The inlet end of the mud suction hose 460 is engaged with the first limiting hole 501 on the first ear plate 500 on the inner wall of the first filter ring 332, and the inlet end of the groundwater suction hose 470 is engaged with the second limiting hole 601 on the second ear plate 600 on the inner wall of the second filter ring 333. Both the first limiting hole 501 and the second limiting hole 601 extend vertically so that the two inlet ends move vertically synchronously with the filter section 330. The lifting drive section 310 drives the connecting assembly 320 to move vertically, so that the filter section 330 and the rotary drilling section 340 move synchronously. The cutterhead assembly 342 directly rotary drills in the soil to be excavated 10 to form a temporary drainage well 30 without a wall pipe, meaning that the wall of the temporary drainage well 30 is not equipped with a permanent wall pipe. The filter section 330 moves down synchronously with the rotary drilling section 340. During the rotary drilling process, the slurry entering the temporary drainage well 30 is filtered in stages by the first filter ring 332 and the second filter ring 333, allowing groundwater to pass through the second filter ring 333 and enter the groundwater suction chamber 302. The first pump body 410 is used to extract the slurry from the slurry suction chamber 301 via the slurry suction hose 460, and the second pump body 420 is used to extract the groundwater from the groundwater suction chamber 302 via the groundwater suction hose 470. Furthermore, during the excavation of the foundation pit, the stroke of the lifting drive section 310 is adjusted synchronously according to the depth of descent of the excavation face, so that the rotary drilling section 340 always remains ahead of the current preset depth of the excavation face, maintaining the effective dewatering depth of the temporary drainage well 30.

[0019] It should be noted that during the well construction and pumping process, the well wall of the temporary drainage well 30 without a well wall pipe is maintained stable by the stratum itself or by auxiliary wall protection measures. This invention is applicable to non-collapse strata such as cohesive soil, silty clay, and silt with a certain self-stabilizing ability of the well wall; for easily collapsed strata such as sandy soil and fine sand, if a bare hole is directly constructed without support, the well wall is prone to collapse under the disturbance of rotary drilling and the seepage of groundwater. The collapsed soil entering the well will cause the filter section 330 to be buried and the inlet ends of the mud suction hose 460 and the groundwater suction hose 470 to be blocked, resulting in pumping failure. Therefore, the present invention further provides the following auxiliary wall protection measures for easily collapsed strata: (1) Mud column pressure wall protection, by adjusting the suction flow rate of the first pump body 410, the mud level in the well is controlled to always be 0.5m to 1.5m higher than the surrounding groundwater level, and the mud column pressure in the well is used to balance the soil pressure of the well wall and suppress the collapse of the well wall; (2) Wall protection slurry wall protection, by injecting bentonite mud or polymer wall protection slurry into the well, so that the wall protection slurry penetrates into the surface soil of the well wall to form mud cake or cemented layer, thereby improving the self-stabilizing ability of the well wall soil; (3) Wall protection cylinder and pipe wall protection, by setting a synchronous connection component 320 around the filter part 330. The lowered retaining wall tube is a thin-walled tube with filter holes on its circumference. Its outer wall is attached to the well wall and forms temporary support for the well wall. Groundwater enters the filter section 330 radially through the filter holes on the retaining wall tube. The retaining wall tube is a recyclable temporary retaining wall component rather than a permanent well wall tube. After pumping is completed, it can be pulled out and recycled with the whole device without affecting the well-forming method without a well wall tube; (4) Control the well-forming and pumping rhythm. In the easily collapsed strata, appropriately reduce the advance depth of the rotary drilling section 340, reduce the rotary drilling sinking speed, and simultaneously adjust the pumping flow rate of the first pump body 410 to maintain the mud level in the well and shorten the exposure time of the well wall without support. Through the above auxiliary retaining wall measures, the present invention can also maintain the stability of the well wall in the easily collapsed strata, ensure the smooth flow of the filter section 330 and the dewatering mechanism 400, prevent pumping failure, and thus expand the applicable strata range of the present invention.

[0020] Specifically, after the mounting frame 100 and the support frame 200 are hinged together, the inclined state of the support frame 200 presses the mounting frame 100 against the surface of the slope 20, and the bottom end of the support frame 200 abuts against the soil to be excavated 10 to form a triangular support; the lifting drive unit 310 drives the connecting assembly 320 to move vertically downward, the connecting assembly 320 drives the filtering unit 330 and the rotary drilling unit 340 to move downward synchronously, the rotary drilling drive unit 341 drives the cutter head assembly 342 to rotate around the vertical axis, the cutter head assembly 342 rotates and cuts and advances downward in the soil to be excavated 10, thereby directly forming a vertical temporary drainage well 30 without a well wall pipe; at the same time, the filtering unit 330 moves downward synchronously with the connecting assembly 320 without rotating, the first filter ring 332 and the second filter ring 333 filter the inflowing temporary drainage well during the rotary drilling process. The mud in well 30 is filtered in stages. Large particles in the mud are blocked in the mud suction chamber 301, and only groundwater filtered by the second filter ring 333 is allowed to enter the groundwater suction chamber 302. The inlet end of the mud suction hose 460 is fixed by the first limiting hole 501 of the first ear plate 500, and the inlet end of the groundwater suction hose 470 is fixed by the second limiting hole 601 of the second ear plate 600. The two inlet ends move down synchronously with the filter section 330. The first pump body 410 and the second pump body 420 are fixed on the support frame 200. The first hose reel 430 and the second hose reel 440 rotate to retract and extend the hose, so that the first pump body 410 continuously pumps out the mud in the mud suction chamber 301 and the second pump body 420 continuously pumps out the filtered groundwater in the groundwater suction chamber 302.

[0021] It should also be noted that the connecting assembly 320, driven by the lifting drive unit 310, only moves linearly vertically and does not rotate around its own axis. The filter unit 330 is fixedly connected to the outer wall of the connecting assembly 320 via the mounting base plate 331. Therefore, the filter unit 330 and its first ear plate 500 and second ear plate 600 do not rotate circumferentially. The connecting end of the rotary drilling drive unit 341 is fixedly installed on the connector 321, and only its output end drives the cutter head assembly 342 to rotate around the vertical axis. The rotational motion is not transmitted to the filter unit 330. Correspondingly, the inlet ends of the mud suction hose 460 and the groundwater suction hose 470 only move vertically with the filter unit 330. Their upper ends are connected to the first pump body 410 and the second pump body 420 fixedly installed on the support frame 200. The rotation of the first hose reel 430 and the second hose reel 440 is only used to release or retrieve the axial length of the hose during the lifting process. Therefore, the two hoses will not accumulate torsional stress during the entire operation, and will not become tangled or twisted. Reliable continuous suction can be achieved without the need for anti-tangling components such as swivel joints.

[0022] To address the current technical problems in ultra-large and ultra-deep foundation pits, such as the difficulty of using primary wells to lower the deep confined water level to a safe elevation, the long well-construction cycle of conventional secondary wells, significant construction interference, difficulty in adjusting synchronously with the excavation face leading to the risk of sudden inrush, and the need to improve overall efficiency, this application implements the following process using the aforementioned structure: First, the mounting frame 100 and support frame 200 are installed at a predetermined position on the foundation pit slope 20. The device is stably fixed by utilizing the inclined hinge structure of the support frame 200 and the bottom abutment action; then, the lifting drive unit 310 is activated, causing the connecting component 320 to drive the filter unit 330 and the rotary drilling unit 340. Maintaining a certain vertical spacing, the rotary drilling drive 341 drives the cutterhead assembly 342 to rotate around the vertical axis, directly rotary drilling to form a temporary drainage well 30 without a well wall pipe. The filter section 330 does not rotate but moves downwards accordingly. The first filter ring 332 and the second filter ring 333 perform graded filtration of the mud in the well in real time and guide the surrounding groundwater radially into the groundwater suction chamber 302. Subsequently, the first pump body 410 and the second pump body 420 continuously extract the corresponding media through the mud suction hose 460 and the groundwater suction hose 470, respectively, to achieve targeted auxiliary dewatering of local deep confined water or complex aquifers. During the excavation of the foundation pit, the stroke of the lifting drive 310 is adjusted according to the descent of the excavation face, so that the rotary drilling section 340 is kept ahead of the current excavation face at a preset depth, thereby maintaining the effective dewatering depth of the temporary drainage well 30.

[0023] In addition, for easily collapsed formations such as sandy soil and fine sand, auxiliary wall protection measures such as mud column pressure wall protection, wall protection slurry wall protection, or wall protection cylinder and pipe wall protection can also maintain well wall stability and ensure smooth pumping, thereby expanding the applicable formation range of the device and better meeting the current construction needs of deep foundation pit engineering for speed, safety and economy.

[0024] As can be seen from the implementation process of the above structure, this application can complete auxiliary dewatering without adding a large number of secondary wells, and can achieve well construction and pumping simultaneously without installing well wall pipes. This can shorten the well construction and relocation operation time, reduce the accumulation of local water pressure caused by the lag of dewatering over excavation, reduce the risk of sudden slab collapse, and at the same time reduce equipment occupation space and operating costs.

[0025] In one implementation, the mounting frame 100 can be fixed at different heights on the slope 20 using a multi-point anchoring method. The tilt angle of the support frame 200 can be adjusted within a certain range. A lockable stop pin is provided at its top hinge point, and its bottom end abuts against the soil to be excavated 10, so as to form a stable triangular support system under different soil conditions on the slope 20. The lifting drive unit 310 can use a hydraulic cylinder as its power source. The lower end of the connecting component 320 is fixedly connected to the rotary drilling drive component 341. The filter unit 330... The mounting base plate 331 is fixedly connected to the outer wall of the connecting assembly 320. The rotary drilling drive 341 drives the cutterhead assembly 342 to rotate around the vertical axis. The filter section 330 does not participate in the rotation. The vertical distance between the rotary drilling section 340 and the filter section 330 can be adjusted according to the soil conditions. The inlet ends of the mud suction hose 460 and the groundwater suction hose 470 are respectively secured in the filter section 330 through the first ear plate 500 and the second ear plate 600 to ensure that they are in a better filtration position during the sinking process. In this embodiment, the adjustment range and connection form of each component enable the device to adapt to different hydrogeological conditions. During implementation, the sequence of direct rotary drilling, synchronous graded filtration, and synchronous pumping is still followed, so that the formation of the temporary drainage well 30 and the groundwater pumping are kept in dynamic balance.

[0026] Please continue reading. Figures 1 to 6 In an embodiment of the present invention, the filter section 330 further includes a mounting base plate 331, which is fixedly connected to the outer wall of the connecting assembly 320. The first filter ring 332 extends along the periphery of the mounting base plate 331 and is fixedly connected to the mounting base plate 331. The second filter ring 333 is coaxially arranged with the first filter ring 332. The groundwater suction chamber 302 is formed between the second filter ring 333 and the connecting assembly 320.

[0027] Specifically, after the mounting frame 100 is fixed to the slope 20 of the foundation pit, the support frame 200 is inclined and its bottom end abuts against the soil to be excavated 10. When the lifting drive unit 310 drives the connecting assembly 320 to move vertically, the mounting base plate 331 fixedly connected to the outer wall of the connecting assembly 320 rises and falls synchronously with the connecting assembly 320. The first filter ring 332 extends along the periphery of the mounting base plate 331 and is fixedly connected to the mounting base plate 331. The second filter ring 333 is coaxially arranged with the first filter ring 332. The first filter ring 332 is sleeved on the outside of the second filter ring 333. A mud suction cavity 301 is formed between the first filter ring 332 and the second filter ring 333. A groundwater suction cavity 302 is formed on the inner periphery of the second filter ring 333, that is, between the second filter ring 333 and the connecting assembly 320. The two cavities are interconnected through the filter holes on the second filter ring 333. During rotary drilling, the rotary drilling drive 341 drives the cutterhead assembly 342 to rotate and directly drill to form a temporary drainage well 30 without a well wall pipe. A large amount of mud enters the mud suction chamber 301 along with the groundwater. Large particles in the mud are blocked by the first filter ring 332 and the second filter ring 333 and deposited in the mud suction chamber 301. The filtered groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302. Then, the first pump body 410 pumps out the mud in the mud suction chamber 301 through the mud suction hose 460, and the second pump body 420 pumps out the groundwater in the groundwater suction chamber 302 through the groundwater suction hose 470.

[0028] This application implements the following process through the above structure: First, a stable working platform is formed by the mounting frame 100, support frame 200 and rotary drilling mechanism 300. The lifting drive unit 310 drives the mounting base plate 331, the first filter ring 332 and the second filter ring 333 to sink synchronously through the connecting component 320. While the cutterhead assembly 342 rotates below to directly form a well, the mixture of mud and groundwater first enters the mud suction chamber 301. The double-layer coaxial filter structure formed by the first filter ring 332 and the second filter ring 333 classifies and blocks the mud, allowing only groundwater to enter the groundwater suction chamber 302 through the filter holes on the second filter ring 333. The first pump body 410 and the second pump body 420 then extract the medium from the two chambers respectively.

[0029] As can be seen from the implementation process of the above structure, the mounting base plate 331 securely connects the first filter ring 332 to the connecting component 320, so that the filter part 330 rises and falls synchronously with the connecting component 320 without rotating. The dual-cavity structure formed by the first filter ring 332 and the second filter ring 333 realizes the graded separation of mud and groundwater, which not only reduces the blockage of the dewatering mechanism 400 by mud, but also ensures that the groundwater is efficiently extracted. Thus, based on the initial dewatering of the first-stage well, real-time auxiliary dewatering of local deep confined water or complex aquifers is achieved, reducing the risk of sudden surge damage to the foundation pit bottom plate, shortening the auxiliary dewatering operation time, and reducing the space occupied by equipment in the foundation pit.

[0030] In one implementation, the mounting base plate 331 can be detachably and fixedly connected to the outer wall of the connecting assembly 320. The first filter ring 332 extends vertically along the periphery of the mounting base plate 331 and is fixedly connected to it. The second filter ring 333 is coaxial with the first filter ring 332 and has a uniform gap. The first filter ring 332 is fitted over the second filter ring 333, forming a mud suction chamber 301 between them. A groundwater suction chamber 302 is formed on the inner periphery of the second filter ring 333. The volume of the mud suction chamber 301 is larger than that of the groundwater suction chamber 302. The inlet ends of the mud suction hose 460 and the groundwater suction hose 470 are fixed to the upper part of the mud suction chamber 301 and the lower part of the groundwater suction chamber 302, respectively. In this implementation, different connection methods and chamber volume ratios allow the device to adapt to soil layers with different mud contents. During implementation, the lifting drive unit 310 drives the filter unit 330 and the rotary drilling unit 340 to move vertically in sync through the connecting component 320. The first filter ring 332 and the second filter ring 333 continuously perform graded filtration. The dewatering mechanism 400 adjusts the suction volume according to the depth of the excavation face descent, so that the rotary drilling unit 340 remains ahead of the current excavation face preset depth.

[0031] Please continue reading. Figures 1 to 5 In an embodiment of the present invention, the cutter head assembly 342 is coaxially arranged with the first filter ring 332, the cutter head assembly 342 is located below the mounting base plate 331 and is vertically spaced by a preset distance from the mounting base plate 331, and the output end of the rotary drilling drive 341 is connected to the cutter head assembly 342.

[0032] Specifically, after the mounting frame 100 and the support frame 200 together form a stable working platform, the lifting drive unit 310 drives the connecting assembly 320 to move vertically downward. The rotary drilling drive unit 341 installed at the lower end of the connecting assembly 320 moves down synchronously with the connecting assembly 320. Its output end is connected to the cutter head assembly 342 and drives the cutter head assembly 342 to rotate around the vertical axis. The cutter head assembly 342 and the first filter ring 332 are coaxial and are located directly below the mounting base plate 331, maintaining a preset distance between them. During the dewatering process during foundation pit excavation, the cutterhead assembly 342 rotates and cuts the soil to be excavated 10, directly forming a temporary drainage well 30 without a well wall pipe. At the same time, the first filter ring 332 and the second filter ring 333 move down synchronously with the mounting base plate 331 without rotating. The mud in the well first enters the mud suction chamber 301 and is blocked and separated by the double-layer filter rings. The groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302. The first pump body 410 and the second pump body 420 continuously extract the corresponding medium from the two chambers.

[0033] This application implements the following process through the above structure: First, a mounting frame 100 and a support frame 200 are installed on the slope 20 to form a fixed platform. The lifting drive unit 310 drives the entire rotary drilling mechanism 300 to sink through the connecting component 320. The rotary drilling drive component 341 installed at the lower end of the connecting component 320 drives the cutter head assembly 342 to rotate around the vertical axis to cut the soil, directly forming a temporary drainage well 30 without a well wall pipe. The vertical preset distance maintained between the cutter head assembly 342 and the mounting base plate 331 ensures that the rotary drilling surface is kept ahead of the filter surface by a certain height, so that the mud and groundwater mixture enters the mud suction chamber 301 and the groundwater suction chamber 302 in an orderly manner during the rising process. After the first filter ring 332 and the second filter ring 333 classify and block the mud, the first pump body 410 and the second pump body 420 simultaneously extract the corresponding medium.

[0034] As can be seen from the implementation process of the above structure, the rotary drilling drive component 341 is installed at the lower end of the connecting component 320 and drives the cutterhead assembly 342 to rotate around the vertical axis, ensuring the transmission of cutting power and the stable advancement of the rotary drilling face. The coaxial arrangement of the cutterhead assembly 342 and the first filter ring 332 and the preset distance maintained with the mounting base plate 331 realize the dynamic following of direct well formation and filtration. This not only reduces the blockage caused by excessive mud entering the suction chamber, but also ensures that groundwater is extracted in time. Thus, based on the initial dewatering of the first-stage well, real-time auxiliary dewatering is carried out on local deep confined water or complex aquifers, reducing the risk of sudden surge damage to the foundation pit bottom plate, shortening the auxiliary dewatering operation cycle, and reducing the space occupied by equipment in the foundation pit and the repeated relocation process.

[0035] In one implementation, the rotary drilling drive 341 can be a hydraulic motor mounted on the lower end of the connecting assembly 320. Its output end is connected to the cutterhead assembly 342 via a coupling. The cutterhead assembly 342 is coaxial with the first filter ring 332. The cutterhead assembly 342 is positioned below the mounting base plate 331 and maintains an adjustable vertical distance from the mounting base plate 331. The preset distance can be selected within the range of 300mm to 800mm based on the soil permeability coefficient. The rotary drilling drive 341 can be linked with the lifting drive unit 310 to maintain the matching of rotational speed and sinking speed. In this implementation, different drive types and distance adjustment ranges allow the device to adapt to soil layers with different permeability coefficients and mud contents. During implementation, the lifting drive unit 310 drives the mounting base plate 331, the first filter ring 332, the second filter ring 333, and the rotary drilling drive unit 341 to move vertically in sync via the connecting component 320. The rotary drilling drive unit 341 drives the cutterhead assembly 342 to rotate and complete the cutting. The mud suction chamber 301 and the groundwater suction chamber 302 continuously separate and collect. The dewatering mechanism 400 adjusts the suction flow rate according to the real-time water level monitoring data, so that the temporary drainage well 30 is kept ahead of the preset depth of the excavation face.

[0036] Please continue reading. Figures 1 to 5In an embodiment of the present invention, the cutter head assembly 342 includes a cutter head body 343, a plurality of first rotary cutting protrusions 344 and a connecting shaft 345. The cutter head body 343 and the first filter ring 332 are coaxially arranged. The orthographic projection area of ​​the first filter ring 332 on the cutter head body 343 is smaller than the orthographic projection area of ​​the cutter head body 343. The cutter head body 343 is connected to the output end of the rotary drilling drive 341 through the connecting shaft 345. The plurality of first rotary cutting protrusions 344 are spaced apart at the bottom end of the cutter head body 343, and the plurality of first rotary cutting protrusions 344 extend vertically.

[0037] Specifically, after the mounting frame 100 and the support frame 200 together form a stable working platform, the lifting drive unit 310 drives the connecting assembly 320 to move vertically downward. The rotary drilling drive unit 341 installed at the lower end of the connecting assembly 320 moves down synchronously with the connecting assembly 320. Its output end transmits torque to the cutter head body 343 through the connecting shaft 345, causing the cutter head body 343 to rotate around the vertical axis. The cutter head body 343 and the first filter ring 332 are coaxially configured, and the orthogonal projection area of ​​the first filter ring 332 on the cutter head body 343 is smaller than the orthogonal projection area of ​​the cutter head body 343, so that the outer periphery of the cutter head body 343 is exposed to the radially outer side of the first filter ring 332. Multiple first rotary cutting protrusions 344 are fixed at intervals at the bottom end of the cutter head body 343 and extend vertically. During the dewatering process during foundation pit excavation, the first rotary cutting protrusion 344 first contacts the soil to be excavated 10 and cuts it. The cutterhead body 343 directly rotary excavates to form a temporary drainage well 30 without a well wall pipe. The mud and groundwater mixture generated by cutting flows upward along the outer periphery of the cutterhead body 343. Since the projected area of ​​the first filter ring 332 is smaller than the projected area of ​​the cutterhead body 343, the mixture can enter the mud suction chamber 301 in an orderly manner. After passing through the graded blocking of the first filter ring 332 and the second filter ring 333, the groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302. The first pump body 410 and the second pump body 420 simultaneously extract the corresponding medium from the two chambers.

[0038] This application implements the following process through the above structure: First, a mounting frame 100 and a support frame 200 are installed on the slope 20 to provide a fixed foundation. The lifting drive unit 310 drives the rotary drilling drive unit 341, the cutterhead body 343 and the filter unit 330 to sink synchronously through the connecting component 320. The rotary drilling drive unit 341 drives the cutterhead body 343 to rotate around the vertical axis through the connecting shaft 345. Multiple first rotary cutting protrusions 344 extending vertically continuously cut the soil, so that the temporary drainage well 30 without well wall pipe is quickly formed. At the same time, the coaxial arrangement and projected area relationship between the cutterhead body 343 and the first filter ring 332 ensure that the cutting surface is kept ahead of the filter surface by a certain distance. The mixture generated by cutting enters the mud suction chamber 301 along the outer periphery of the cutterhead body 343 and is effectively separated by the double-layer filter ring. The dewatering mechanism 400 extracts the filtered groundwater in real time.

[0039] As can be seen from the implementation process of the above structure, the connecting shaft 345 reliably connects the output end of the rotary drilling drive 341 to the cutterhead body 343 and transmits torque. The multiple vertically extending first rotary cutting protrusions 344 enhance the cutting efficiency and form a channel that facilitates the upward flow of the mixture. The configuration of the first filter ring 332 having a smaller projected area than the cutterhead body 343 provides radial space for the mud to enter the suction chamber, which not only improves the well completion speed but also ensures the continuity of media separation in the filter section 330. Thus, based on the initial dewatering of the first-stage well, real-time auxiliary dewatering can be carried out on local deep confined water or complex aquifers, reducing the risk of sudden surge damage to the foundation pit floor, shortening the auxiliary dewatering operation cycle, and reducing the space occupied by equipment in the foundation pit and the repeated relocation process.

[0040] In one embodiment, the cutterhead body 343 can be connected to the output end of the rotary drilling drive 341 via a splined connecting shaft 345. The cutterhead body 343 and the first filter ring 332 are coaxial. The ratio of the projected area of ​​the first filter ring 332 on the cutterhead body 343 to the projected area of ​​the cutterhead body 343 can be adjusted within the range of 0.65 to 0.85. Multiple first rotary cutting protrusions 344 are evenly spaced at the bottom of the cutterhead body 343 and extend vertically to a position higher than the lower surface of the mounting base plate 331. The rotary drilling drive 341 and the lifting drive unit 310 can be linked by a control unit to maintain the leading relationship between the cutting surface and the filter surface. In this embodiment, different connection forms, projected area ratios, and the number of protrusions enable the device to adapt to soil layers with different hardness and permeability coefficients. During implementation, the lifting drive unit 310 drives the mounting base plate 331, the first filter ring 332, the second filter ring 333, and the rotary drilling drive unit 341 to move vertically in sync via the connecting component 320. The rotary drilling drive unit 341 drives the cutterhead body 343 to rotate, and multiple vertically extending first rotary cutting protrusions 344 continuously cut the soil. The projected area relationship ensures that the flow path of the mixture is unobstructed. The mud suction chamber 301 and the groundwater suction chamber 302 continuously complete the separation and collection. The dewatering mechanism 400 adjusts the suction flow rate according to the descent depth of the excavation face, so that the temporary drainage well 30 is kept ahead of the current excavation face preset depth.

[0041] Please continue reading. Figures 1 to 5 In an embodiment of the present invention, the cutter head assembly 342 further includes a plurality of second rotary cutting protrusions 346, which extend radially along the cutter head body 343 and are spaced apart along the periphery of the cutter head body 343 and fixedly connected to the cutter head body 343.

[0042] Specifically, after the mounting frame 100 and the support frame 200 together form a stable working platform, the lifting drive unit 310 drives the connecting assembly 320 to move vertically downward. The rotary drilling drive unit 341 installed at the lower end of the connecting assembly 320 drives the cutter head body 343 to rotate around the vertical axis. Multiple first rotary cutting protrusions 344 fixed at the bottom of the cutter head body 343 extend vertically to perform initial cutting on the soil. Multiple second rotary cutting protrusions 346 fixed at the periphery of the cutter head body 343 and extending radially rotate synchronously with the cutter head body 343 to perform secondary crushing on large mud blocks. During the formation of the temporary drainage well 30 without a well wall pipe, the larger mud blocks produced by the first rotary cutting protrusion 344 collide and shear with the rotating second rotary cutting protrusion 346 during the upward process, and are further broken into fine particles that can pass through the gap between the first filter ring 332 and the second filter ring 333, and then enter the mud suction chamber 301. The groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302. The first pump body 410 and the second pump body 420 continuously extract the corresponding media from the two chambers.

[0043] This application implements the following process through the above structure: First, a mounting frame 100 and a support frame 200 are installed on the slope 20 to form a fixed platform. The lifting drive unit 310 drives the rotary drilling drive unit 341, the cutter head body 343 and the filter unit 330 to sink synchronously through the connecting component 320. The rotary drilling drive unit 341 drives the cutter head body 343 to rotate around the vertical axis. After the first rotary cutting protrusions 344 extending vertically complete the initial cutting, the second rotary cutting protrusions 346 extending radially and arranged at intervals along the periphery further crush the large mud blocks, reducing their size to the point where they can smoothly enter the mud suction chamber 301. The crushed mud is effectively blocked by the first filter ring 332 and the second filter ring 333 in the mud suction chamber 301, while the groundwater enters the groundwater suction chamber 302 and is extracted by the second pump body 420.

[0044] As can be seen from the implementation process of the above structure, after the second rotary cutting protrusion 346 extends radially along the cutterhead body 343 and is fixedly connected to the cutterhead body 343, it generates a continuous shearing action as the cutterhead body 343 rotates, breaking large mud blocks into particles suitable for passing through the filter gap. This ensures the unobstructed flow of the mud suction chamber 301 and maintains the purity of the groundwater in the groundwater suction chamber 302. Thus, based on the initial dewatering of the primary well, it enables real-time auxiliary dewatering of local deep confined water or complex aquifers, reducing the risk of sudden collapse of the foundation pit bottom slab, shortening the auxiliary dewatering operation cycle, and reducing the number of equipment maintenance times and site occupation in the foundation pit.

[0045] In one implementation, multiple second rotary cutting protrusions 346 can be evenly spaced along the periphery of the cutterhead body 343, and the ratio of their radial extension length to the radius of the cutterhead body 343 can be selected within a certain range. The second rotary cutting protrusions 346 and the cutterhead body 343 can be detachably fixedly connected, so that second rotary cutting protrusions 346 of different heights and angles can be replaced according to different soil layer characteristics. The coaxiality and projected area relationship between the cutterhead body 343 and the first filter ring 332 remain unchanged. The rotational speed of the rotary drilling drive 341 and the sinking speed of the lifting drive 310 can be matched by the linkage control unit to maintain a constant crushing and filtering synergy. In this implementation, different numbers, radial extension ratios, and connection methods enable the device to adapt to highly viscous soil layers or soil layers containing large pieces of gravel. During implementation, the lifting drive unit 310 drives the mounting base plate 331, the first filter ring 332, the second filter ring 333, and the cutter head assembly 342 to move vertically in sync via the connecting component 320. The rotary drilling drive unit 341 drives the cutter head body 343 to rotate. After the first rotary cutting protrusion 344 completes the initial cutting, the second rotary cutting protrusion 346 performs secondary crushing on large mud blocks. The crushed fine mud enters the mud suction chamber 301 in an orderly manner. The mud suction chamber 301 and the groundwater suction chamber 302 continuously complete separation and collection. The dewatering mechanism 400 adjusts the suction flow rate according to the real-time monitored water level and mud concentration, so that the temporary drainage well 30 is kept ahead of the current excavation face preset depth. Thus, even under complex multi-layer aquifer and high-viscosity strata conditions, the filter unit 330 can still maintain long-term unobstructed and stable drainage efficiency.

[0046] Please continue reading. Figures 1 to 6 In an embodiment of the present invention, the connecting component 320 includes a connector 321 and an annular cage 322. The annular cage 322 is sleeved on the outer wall of the connector 321 and fixedly connected to the connector 321. The connecting end of the rotary drilling drive 341 is installed on the bottom end of the connector 321 through the annular cage 322. The mounting base plate 331 is installed on the outer wall of the connector 321 and is disposed near the lower end of the connector 321.

[0047] Specifically, after the mounting frame 100 and the support frame 200 together form a stable working platform, the lifting drive unit 310 drives the connecting assembly 320 to move vertically downward. After the annular cage 322 is fitted onto the outer wall of the connector 321 and fixedly connected to the connector 321, the connecting end of the rotary drilling drive 341 is securely installed at the bottom of the connector 321, so that the torque output by the rotary drilling drive 341 is transmitted to the lower cutter head assembly 342. The mounting base plate 331 is installed on the outer wall of the connector 321 and is set near the lower end of the connector 321, and rises and falls synchronously with the connector 321. The filter unit 330 rises and falls synchronously with the connecting assembly 320 without rotating. During the formation of the temporary drainage well 30 without a well wall pipe, the mixture generated by cutting below the cutterhead body 343 first enters the mud suction chamber 301. After being blocked by the first filter ring 332 and the second filter ring 333, the groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302 formed between the second filter ring 333 and the connector 321. The second pump body 420 extracts groundwater from the groundwater suction chamber 302 through the groundwater suction hose 470, and the first pump body 410 extracts mud from the mud suction chamber 301 through the mud suction hose 460.

[0048] This application implements the following process through the above structure: First, a fixed platform is formed by installing a mounting frame 100 and a support frame 200 on the slope 20. The lifting drive unit 310 drives the connector 321, the annular cage 322, the mounting base plate 331, the first filter ring 332, the second filter ring 333, and the rotary drilling drive component 341 to move vertically in sync through the connecting component 320. After the annular cage 322 is fixedly connected to the connector 321, the rotary drilling drive component 341 is securely installed at the bottom of the connector 321 to ensure overall coaxiality and vertical stability during the rotary cutting process. The mounting base plate 331 is set near the lower end of the connector 321 so that the filter unit 330 is close to the cutter head assembly 342. The groundwater suction chamber 302 formed between the second filter ring 333 and the connector 321 serves as an inner annular space, allowing the groundwater filtered by the second filter ring 333 to collect here and be pumped out by the second pump body 420. This implementation process allows for the continuous completion of connection fixation, synchronous lifting, mud grading and blocking, and groundwater extraction within the same vertical stroke.

[0049] As can be seen from the implementation process of the above structure, after the annular cage 322 is fitted onto the outer wall of the connector 321 and fixedly connected, it provides circumferential support for the rotary drilling drive 341 and ensures the rigidity of the torque transmission path. The positional relationship of the mounting base plate 331 at the lower end of the connector 321 makes the filter part 330 close to the cutting surface. The groundwater suction chamber 302 formed between the second filter ring 333 and the connector 321 shortens the groundwater collection path. This maintains the overall stability of the filter part 330 during rotary cutting and improves the targeting and efficiency of groundwater extraction. Thus, based on the initial dewatering of the primary well, real-time auxiliary dewatering is carried out on local deep confined water or complex aquifers, reducing the risk of sudden surge damage to the foundation pit bottom plate, shortening the auxiliary dewatering operation cycle, and reducing the number of equipment maintenance and site occupation in the foundation pit.

[0050] In one implementation, the annular cage 322 can be fixedly connected to the outer wall of the connector 321 by multiple sets of bolts. The connecting end of the rotary drilling drive 341 is installed at the bottom end of the connector 321 via the annular cage 322 using a flange. The mounting base plate 331 can be welded to the outer wall of the connector 321 and is located within a certain range above the lower end of the connector 321. The radial distance between the second filter ring 333 and the connector 321 can be maintained within a certain range to form a groundwater suction chamber 302. A guide hole can be provided inside the connector 321 to allow the slurry discharge pipeline to pass along the center. In this implementation, different fixing methods, installation height ranges, and chamber spacing allow the device to adapt to different depths and soil conditions. During implementation, the lifting drive unit 310 drives the connector 321 and all lower components to move vertically synchronously via the connecting component 320. The annular cage 322 fixes the rotary drilling drive 341 to the bottom of the connector 321. The mounting base 331 ensures that the starting point of the first filter ring 332 is close to the cutterhead body 343. The groundwater suction chamber 302 continuously receives groundwater passing through the second filter ring 333. The dewatering mechanism 400 adjusts the suction ratio of the two chambers according to real-time water level data, so that the temporary drainage well 30 is kept ahead of the current excavation face at a preset depth. Under the conditions of high-pressure multi-layer aquifers, this embodiment can maintain the long-term rigidity of the connecting component 320 and the stable coordination of filtration and drainage.

[0051] Please continue reading. Figures 1 to 6 In an embodiment of the present invention, the precipitation mechanism 400 further includes an installation rod 450, which is detachably installed on the support frame 200. The first hose reel 430 and the second hose reel 440 are respectively rotatably sleeved on the installation rod 450. The first pump body 410 and the second pump body 420 are fixedly installed at intervals at one end of the support frame 200 away from the slope 20.

[0052] Specifically, after the mounting frame 100 and the support frame 200 together form a stable working platform, the first pump body 410 and the second pump body 420 are fixedly installed at intervals on the end of the support frame 200 away from the slope 20. The mounting rod 450 is detachably installed on the support frame 200. The first hose reel 430 and the second hose reel 440 are respectively rotatably sleeved on the mounting rod 450 to realize the automatic extension and retraction of the hose length during the lifting process. The mud suction hose 460 is wound around the first hose reel 430, its inlet end extends into the mud suction chamber 301, and its outlet end is connected to the inlet end of the first pump body 410. The groundwater suction hose 470 is wound around the second hose reel 440, its inlet end extends into the groundwater suction chamber 302, and its outlet end is connected to the inlet end of the second pump body 420. During the dewatering process during foundation pit excavation, when the lifting drive unit 310 drives the connecting assembly 320, the filter unit 330, and the rotary drilling unit 340 to move vertically downwards in sync, the first hose reel 430 and the second hose reel 440 rotate and extend the hoses of the corresponding lengths, so that the inlet end of the mud suction hose 460 is always at a suitable depth in the mud suction chamber 301, and the inlet end of the groundwater suction hose 470 is always at a suitable depth in the groundwater suction chamber 302. The first pump body 410 continuously draws out the mud that has been blocked by the first filter ring 332 and the second filter ring 333 from the mud suction chamber 301, and the second pump body 420 continuously draws out the filtered groundwater from the groundwater suction chamber 302.

[0053] This application implements the following process through the above structure: First, the mounting frame 100 and the support frame 200 are installed on the slope 20. After the bottom end of the support frame 200 abuts against the soil to be excavated 10, the first pump body 410 and the second pump body 420 are fixedly installed on the end of the support frame 200 away from the slope 20. After the mounting rod 450 is disassembled and installed on the support frame 200, the first hose reel 430 and the second hose reel 440 are sleeved on it. When the lifting drive unit 310 drives the connecting assembly 320 to move down, the multiple first rotary cutting protrusions 344 and the multiple second rotary cutting protrusions 346 on the cutter head body 343 rotate and cut the soil and directly form a wellless structure. The temporary drainage well 30 of the wall pipe allows the mixture generated from the cutting process to enter the mud suction chamber 301, where it is separated by a double-layer filter ring. Large mud chunks are broken up by the second rotary cutting protrusion 346 and pass smoothly through. Groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302 formed between the second filter ring 333 and the connector 321. Simultaneously, the first hose reel 430 and the second hose reel 440 rotate to release the hose length, causing the inlet ends of the mud suction hose 460 and the groundwater suction hose 470 to move down synchronously with the chamber. The first pump body 410 and the second pump body 420 then start suction operations to extract the medium. This process allows direct rotary drilling, mud crushing and grading filtration, groundwater chamber drainage, and adaptive hose length adjustment to be completed continuously within the same vertical stroke.

[0054] As can be seen from the implementation process of the above structure, the first pump body 410 and the second pump body 420 are fixedly installed at the end of the support frame 200 away from the slope 20 and rely on the bottom end of the support frame 200 to abut against the stable foundation of the soil to be excavated 10, ensuring the vibration resistance stability of the pumping operation. The cooperation between the installation rod 450 and the two hose reels realizes the automatic extension and retraction of the hose as it rises and falls with the connecting component 320. The mud suction hose 460 and the groundwater suction hose 470 are respectively connected to the corresponding cavities and pump bodies to form independent suction channels, which not only ensures the separation and discharge of mud and groundwater, but also maintains the dynamic following of the temporary drainage well 30 that is always ahead of the excavation face. Thus, based on the initial dewatering of the first-level pipe well, real-time auxiliary dewatering is carried out on local deep confined water or complex aquifers, reducing the risk of sudden surge damage to the bottom plate of the foundation pit, shortening the auxiliary dewatering operation cycle, and reducing the space occupied by equipment in the foundation pit and the repeated relocation process.

[0055] In one implementation, the first pump body 410 and the second pump body 420 can be fixedly installed at a certain distance from the end of the support frame 200 away from the slope 20. The mounting rod 450 can be detachably installed in the middle of the support frame 200 in a segmented connection form. The first hose reel 430 and the second hose reel 440 are respectively sleeved on the mounting rod 450 through bearings and can be equipped with a tension control unit. The inlet end of the mud suction hose 460 can be equipped with a filter screen and extends into the bottom of the mud suction chamber 301. The inlet end of the groundwater suction hose 470 can be equipped with a sedimentation section and extends into the middle of the groundwater suction chamber 302. The first pump body 410 and the second pump body 420 can be controlled by frequency conversion and linked with a water level monitoring sensor to adjust the suction flow rate. In this implementation, different installation spacing, mounting rod 450 connection forms, and additional structures at the hose ends enable the device to adapt to different pit depths and aquifer permeability coefficients. During implementation, the bottom of the support frame 200 abuts against the soil to be excavated 10 to provide a stable foundation. When the lifting drive unit 310 drives the connecting component 320 to move down, the rotary drilling drive unit 341 drives the cutter head body 343 to rotate. Multiple first rotary cutting protrusions 344 and multiple second rotary cutting protrusions 346 sequentially complete cutting and crushing and directly form a temporary drainage well 30 without a well wall pipe. After the mud and groundwater in the filter unit 330 are separated, the first hose reel 430 and the second hose reel 440 rotate to release the hose. The inlet ends of the mud suction hose 460 and the groundwater suction hose 470 maintain a better suction position as the cavity moves down. The first pump body 410 and the second pump body 420 adjust the speed according to the sensor data to continuously extract the corresponding medium.

[0056] Please continue reading. Figure 1 , Figure 2 , Figure 4 , Figure 5 and Figure 6In an embodiment of the present invention, the first ear plate 500 is welded and fixed to the inner wall of the first filter ring 332, and the second ear plate 600 is fixed to the inner wall of the second filter ring 333 by bolts. The inlet end of the mud suction hose 460 and the inlet end of the groundwater suction hose 470 are respectively provided with clamping connectors to be clamped in the first limiting hole 501 and the second limiting hole 601 respectively.

[0057] Specifically, after the mounting frame 100 and the support frame 200 together form a stable working platform, the first ear plate 500, which is welded and fixed to the inner wall of the first filter ring 332, moves synchronously with the first filter ring 332. The first limiting hole 501 extending vertically on its upper edge locks the liquid inlet end of the mud suction hose 460 into it. The second ear plate 600, which is fixed to the inner wall of the second filter ring 333 by bolts, moves synchronously with the second filter ring 333. The second limiting hole 601 extending vertically on its upper edge locks the liquid inlet end of the groundwater suction hose 470 into it. The clamping joints provided on the two liquid inlets are respectively engaged with the corresponding limiting holes to prevent the liquid inlets from falling off or causing significant radial displacement during the lifting and lowering process. When the lifting drive unit 310 drives the connecting assembly 320 to move vertically downward, the rotary drilling drive unit 341 drives the cutterhead body 343 to rotate around the vertical axis. Multiple first rotary cutting protrusions 344 and multiple second rotary cutting protrusions 346 sequentially complete the initial cutting and crushing of large mud blocks, directly forming a temporary drainage well 30 without a well wall pipe. The resulting mixture enters the mud suction chamber 301 and is blocked by the first filter ring 332 and the second filter ring 333 in stages. Groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302. At the same time, the first ear plate 500 and the second ear plate 600 move down with the filter ring, and drive the two hose inlet ends to move down synchronously through the first limiting hole 501 and the second limiting hole 601. The first hose reel 430 and the second hose reel 440 rotate to release hoses of corresponding lengths, while the positions of the first pump body 410 and the second pump body 420 remain fixed. The main positions of the mud suction hose 460 and the groundwater suction hose 470 remain unchanged, with only the inlet end moving down with the filter unit 330.

[0058] This application implements the following process through the above structure: First, an installation frame 100 and a support frame 200 are installed on the slope 20. After the bottom end of the support frame 200 abuts against the soil to be excavated 10, the first pump body 410 and the second pump body 420 are fixedly installed on the support frame 200. The lifting drive unit 310 drives the filter unit 330 and the rotary drilling unit 340 to move vertically downwards synchronously through the connecting component 320. The first rotary cutting protrusion 344 and the second rotary cutting protrusion 346 on the cutterhead body 343 rotate and cut directly to form a temporary drainage well 30 without a well wall pipe. The cutting mixture is crushed by the second rotary cutting protrusion 346 and enters the mud suction chamber 301 and is separated by a double-layer filter ring. Groundwater enters the ground. In the water suction chamber 302, the first ear plate 500, welded and fixed to the inner wall of the first filter ring 332, moves downward with the ring body. Its vertically extending first limiting hole 501 clamps the inlet end of the mud suction hose 460, making it follow synchronously. The second ear plate 600, fixed to the inner wall of the second filter ring 333 by bolts, moves downward with the ring body. Its vertically extending second limiting hole 601 clamps the inlet end of the groundwater suction hose 470, making it follow synchronously. The first hose reel 430 and the second hose reel 440 rotate to release the hose length to adapt to the downward movement distance. The positions of the first pump body 410 and the second pump body 420, as well as the position of the hose body, do not need to be adjusted to maintain continuous suction. This implementation process allows direct rotary drilling, mud crushing and grading filtration, chambered drainage, and the synchronous following of the hose inlet end to be completed continuously in the same vertical stroke.

[0059] As can be seen from the implementation process of the above structure, the cooperation between the first ear plate 500 and the first limiting hole 501 constrains the liquid inlet end of the mud suction hose 460 to the inner wall of the first filter ring 332 and achieves vertical synchronous movement. The cooperation between the second ear plate 600 and the second limiting hole 601 constrains the liquid inlet end of the groundwater suction hose 470 to the inner wall of the second filter ring 333 and achieves vertical synchronous movement. The welding and bolt fixing methods respectively ensure the reliability of the connection between the first ear plate 500 and the second ear plate 600. The snap-fit ​​connector makes the locking relationship between the liquid inlet end and the limiting hole more secure. Stable; with the first pump body 410 and the second pump body 420 fixed in position, the two inlet ends are always at the optimal suction depth of the corresponding cavity as the filter section 330 moves down. This ensures the real-time separation and discharge of mud and groundwater, and maintains the dynamic following of the temporary drainage well 30 ahead of the excavation face. Thus, based on the initial dewatering of the first-stage well, real-time auxiliary dewatering is carried out on local deep confined water or complex aquifers, reducing the risk of sudden surge damage to the foundation pit bottom slab, shortening the auxiliary dewatering operation cycle, and reducing the space occupied by equipment in the foundation pit and the need for repeated adjustment procedures.

[0060] In one implementation, a plurality of first ear plates 500 are evenly arranged circumferentially on the inner wall of the first filter ring 332. Each first ear plate 500 has a first limiting hole 501 extending vertically. The first ear plate 500 can be fixedly connected to the inner wall of the first filter ring 332 by welding. A plurality of second ear plates 600 are evenly arranged circumferentially on the inner wall of the second filter ring 333. Each second ear plate 600 has a second limiting hole 601 extending vertically. The second ear plate 600 can be detachably fixedly connected to the inner wall of the second filter ring 333 by bolts. The inlet end of the mud suction hose 460 can be fitted with a clamp and then clamped into the first limiting hole 501. The inlet end of the groundwater suction hose 470 can be fitted with a chamfered clamp and then clamped into the second limiting hole 601. The vertical length of the first limiting hole 501 and the second limiting hole 601 is not less than a certain multiple of the maximum stroke of the filter section 330. In this embodiment, different numbers of ear plates, the width ratio of the limiting holes, the fixing method, and the clamping joint structure enable the device to adapt to different hose specifications and pit depths. During implementation, when the lifting drive unit 310 drives the connecting assembly 320 to move downward, the rotary drilling unit 340 rotates and cuts synchronously with the filter unit 330, and the filter unit 330 does not rotate. Multiple first ear plates 500 and multiple second ear plates 600 respectively stably clamp the corresponding hose inlet end through the limiting holes, so that it does not have obvious radial displacement as the ring moves vertically. The first hose reel 430 and the second hose reel 440 rotate to release the hose. The positions of the first pump body 410 and the second pump body 420 are fixed. The suction flow rate is adjusted by frequency conversion, and the two inlet ends are always kept in suitable positions within the mud suction chamber 301 and the groundwater suction chamber 302.

[0061] It should also be noted that in the above embodiments, the preset distance between the filter section 330 and the rotary drilling section 340 along the vertical axis is usually selected in the range of 300mm to 800mm. This distance can be adjusted according to the permeability coefficient, mud content and pressure head of the soil layer to ensure that the rotary drilling surface is always ahead of the filter surface, while avoiding a large amount of mud from flowing into the mud suction chamber 301 and causing blockage.

[0062] The pre-set depth of the rotary drilling unit 340 ahead of the current excavation face is generally controlled within the range of 2.0m to 3.5m. This depth range can be selected according to the excavation speed of the foundation pit, the permeability of the soil layer and the height of the confined water head, so as to ensure that the temporary drainage well 30 can effectively reduce the groundwater level while maintaining the safety and stability of the foundation pit bottom plate.

[0063] Furthermore, the various preset parameters involved in the above embodiments can be adjusted and optimized within reasonable ranges according to the specific hydrogeological conditions, soil permeability coefficient, mud content, confined water head height, and excavation speed of the project, so as to achieve the best balance between the adaptability of the device and method of the present invention and the precipitation effect under different geological environments. Specifically, as follows: The tilt angle of the support frame 200 is 30° to 60°; The vertical distance between the filter section 330 and the rotary drilling section 340 is 300mm to 800mm; The rotary drilling rig 340 extends 2.0m to 3.5m ahead of the current excavation face. The ratio of the projected area of ​​the first filter ring 332 on the cutter head body 343 to the projected area of ​​the cutter head body 343 is 0.65 to 0.85. The volume ratio of the mud suction chamber 301 to the groundwater suction chamber 302 is 1.2:1 to 2.5:1; The number of the first rotary cutting protrusions 344 is 4 to 8, and their vertical extension length is 150mm to 350mm; The number of the second rotary cutting protrusions 346 is 6 to 12, and their radial extension length is 80 mm to 180 mm. The tension control range of the first hose reel 430 and the second hose reel 440 is 15N to 45N; The ratio of the sinking speed of the lifting drive unit 310 to the rotational speed of the rotary drilling drive unit 341 is 1:80 to 1:150 (unit: m / min : r / min).

[0064] In formations prone to borehole collapse, the mud level in the well is 0.5m to 1.5m higher than the surrounding groundwater level. The wall-protecting slurry is bentonite mud or polymer slurry, and its funnel viscosity is 25s to 50s. The inner diameter of the protective wall cylinder is 30mm to 80mm larger than the outer diameter of the filter section 330. The bottom end of the protective wall cylinder extends 0.3m to 1.0m ahead of the bottom end of the filter section 330 in the vertical direction. The opening rate of the filter holes on the peripheral wall of the protective wall cylinder is 10% to 25%.

[0065] Please continue reading. Figures 1 to 6 And see Figure 7 The present invention also proposes a method for assisted dewatering during foundation pit excavation, which utilizes the aforementioned assisted dewatering device for foundation pit excavation. The method includes: Step S10: Fix the mounting frame 100 to the slope 20 of the foundation pit, adjust the tilt angle of the support frame 200 so that the bottom end of the support frame 200 abuts against the soil to be excavated 10, and position the rotary drilling mechanism 300 in the predetermined auxiliary dewatering area. Step S20: Start the lifting drive unit 310, drive the connecting component 320 to drive the filter unit 330 and the rotary drilling unit 340 to move downwards vertically synchronously. The rotary drilling drive unit 341 drives the cutter head assembly 342 to rotate, directly rotary drilling in the soil to be excavated 10 to form a temporary drainage well 30 without well wall pipe. At the same time, the filter unit 330 moves downwards synchronously with the rotary drilling unit 340 without rotating. During the rotary drilling process, the mud entering the well is filtered in stages by the first filter ring 332 and the second filter ring 333, so that the groundwater passes through the second filter ring 333 and enters the groundwater suction chamber 302. Step S30: Activate the dewatering mechanism 400. The first hose reel 430 and the second hose reel 440 rotate to wind up and unwind the hoses, causing the two inlet ends to move down synchronously with the filter section 330. The first pump body 410 extracts the mud from the mud suction chamber 301 through the mud suction hose 460, and the second pump body 420 extracts the groundwater from the groundwater suction chamber 302 through the groundwater suction hose 470, so as to carry out auxiliary dewatering for local deep confined water or complex aquifers on the basis of the initial dewatering of the primary well. In step S40, during the excavation of the foundation pit, the stroke of the lifting drive unit 310 is adjusted synchronously according to the descent depth of the excavation face, so that the rotary drilling unit 340 always stays ahead of the current excavation face preset depth, and maintains the effective dewatering depth of the temporary drainage well 30.

[0066] It should be understood that the foundation pit excavation auxiliary dewatering method uses the aforementioned foundation pit excavation auxiliary dewatering device. The specific structure of the foundation pit excavation auxiliary dewatering device is as described in the above embodiments. Since this foundation pit excavation auxiliary dewatering method adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0067] Specifically, this method is applicable to non-collapse formations such as cohesive soil, silty clay, and silt with a certain self-stabilizing ability of the well wall; when applied to formations such as sandy soil and fine sand that are prone to collapse, auxiliary wall protection measures such as mud column pressure protection, injection of wall protection slurry, or wall protection cylinder and pipe can be taken simultaneously during the well construction process to maintain the stability of the well wall and prevent the well wall from collapsing and burying the filter section 330, which would lead to pumping failure.

[0068] First, the mounting frame 100 is reliably fixed to the slope 20 of the foundation pit by anchor rods. Then, the tilt angle of the support frame 200 is adjusted so that its bottom end is stably abutted against the soil to be excavated 10, forming a stable triangular support system. At the same time, it is ensured that the rotary drilling mechanism 300 is accurately aligned with the center position of the predetermined auxiliary dewatering area.

[0069] Next, the lifting drive unit 310 is activated, driving the connecting assembly 320 to move vertically downwards. The connecting assembly 320 drives the filtering unit 330 and the rotary drilling unit 340 to move vertically downwards synchronously, and the filtering unit 330 moves vertically with the connecting assembly 320 without rotating. The rotary drilling drive unit 341 drives the cutterhead body 343 to rotate around the vertical axis. Multiple first rotary cutting protrusions 344 located at the bottom of the cutterhead body 343 first perform initial vertical cutting on the soil. Multiple second rotary cutting protrusions 346 located around the periphery of the cutterhead body 343 rotate synchronously with the cutterhead body 343, and perform secondary crushing on the large mud blocks generated during the cutting process, reducing their size to be able to pass smoothly through the gap between the first filter ring 332 and the second filter ring 333. The cutterhead assembly 342 directly rotary digs in the soil to be excavated 10 to form the temporary drainage well 30 without a well wall pipe. At the same time, the filter section 330 moves down synchronously with the rotary drilling section 340, and the mounting base plate 331, the first filter ring 332 and the second filter ring 333 move vertically synchronously. After the mud and groundwater mixture generated by cutting enters the mud suction chamber 301, larger particles are effectively blocked by the first filter ring 332 and the second filter ring 333 and deposited in the mud suction chamber 301, while groundwater passes through the filter holes on the second filter ring 333 and enters the groundwater suction chamber 302 formed between the second filter ring 333 and the connector 321.

[0070] Then, the precipitation mechanism 400 is activated. The inlet end of the mud suction hose 460 is reliably locked in place by the first limiting hole 501 on the first ear plate 500 on the inner wall of the first filter ring 332 and moves down synchronously with the first filter ring 332. The inlet end of the groundwater suction hose 470 is reliably locked in place by the second limiting hole 601 on the second ear plate 600 on the inner wall of the second filter ring 333 and moves down synchronously with the second filter ring 333. The inlet ends of the mud suction hose 460 and the groundwater suction hose 470 are respectively provided with clamping connectors to be locked in the corresponding limiting holes. With the coordination of the first hose reel 430 and the second hose reel 440 rotating and extending the hose length, the first pump body 410 and the second pump body 420 remain fixed in position at the end of the support frame 200 away from the slope 20. The first pump body 410 continuously extracts mud from the mud suction chamber 301 through the mud suction hose 460, and the second pump body 420 continuously extracts fully filtered groundwater from the groundwater suction chamber 302 through the groundwater suction hose 470. Thus, based on the initial dewatering of the primary well, real-time auxiliary dewatering of local deep confined water or complex aquifers is achieved during the excavation of the foundation pit.

[0071] Throughout the entire excavation process, the stroke of the lifting drive unit 310 is adjusted synchronously according to the current excavation depth, so that the rotary drilling unit 340 always maintains a preset depth 2.0m to 3.5m ahead of the current excavation surface, ensuring that the bottom of the temporary drainage well 30 is always kept within the effective dewatering depth range.

[0072] To address the technical challenges in current ultra-large and ultra-deep foundation pit construction, where primary manholes struggle to lower groundwater levels to safe elevations across all strata, and conventional secondary manholes suffer from long well-construction cycles, significant construction interference, fixed manhole locations that are difficult to adjust synchronously with the excavation face, potential for sudden water inrushes, and high equipment and operating costs, this application implements the following process using the aforementioned method: First, a stable working platform is formed on the slope 20 using the mounting frame 100 and the support frame 200, and the rotary drilling mechanism 300 is precisely positioned; then, the lifting drive unit 310 is activated to synchronously lower the rotary drilling unit 340 and the filter unit 330 while maintaining a specific vertical distance. The first rotary cutting protrusion 344 and the second rotary cutting protrusion 346 on the cutterhead body 343 sequentially complete the initial cutting and large-block crushing of the mud, and then... A temporary drainage well 30 without a well wall is directly formed by rotary drilling in the excavated soil 10. The first filter ring 332 and the second filter ring 333 in the filter section 330 perform real-time graded filtration of the mixture entering the mud suction chamber 301. After the groundwater enters the groundwater suction chamber 302, it is pumped out by the dewatering mechanism 400. At the same time, the first limiting hole 501 of the first ear plate 500 and the second limiting hole 601 of the second ear plate 600 enable the liquid inlet ends of the two hoses to move down synchronously with the filter section 330, while the first pump body 410 and the second pump body 420 can maintain continuous suction without moving. Finally, the stroke of the lifting drive section 310 is adjusted in real time according to the descent depth of the excavation face, so that the rotary drilling section 340 is always ahead of the preset depth of the excavation face. Through the orderly implementation of the above steps, this method organically combines direct rotary drilling, mud crushing, real-time mud grading and filtration, groundwater drainage, and dynamic depth tracking in the same vertical operation stroke, avoiding the defects of traditional secondary wells, such as independent well construction, installation of well casing, fixed location, easy blockage, and frequent relocation.

[0073] As can be seen from the implementation process of the above method, the stable platform formed by fixing the mounting frame 100 to the slope 20 and adjusting the tilt angle of the support frame 200 provides a reliable foundation for subsequent synchronous operations; the lifting drive unit 310 drives the connecting assembly 320 to make the filter unit 330 and the rotary drilling unit 340 sink synchronously, the filter unit 330 does not rotate, and in conjunction with the cutting and crushing action of the first and second rotary cutting protrusions 346, combined with the double-layer chamber filtration structure of the first filter ring 332 and the second filter ring 333, the mud and... Effective separation of groundwater; the cooperation of the first ear plate 500, the second ear plate 600 with the first limiting hole 501, the second limiting hole 601, and the rotation and unwinding of the first hose reel 430 and the second hose reel 440, enable the inlet end of the dewatering mechanism 400 to move synchronously with the filter section 330 without changing the installation positions of the first pump body 410 and the second pump body 420; finally, the step of synchronously adjusting the stroke of the lifting drive section 310 according to the excavation depth ensures that the temporary drainage well 30 always maintains an effective advanced dewatering depth. Thus, based on the initial dewatering of the primary well, dewatering is achieved on-site for local deep confined water or complex aquifers, significantly reducing the risk of sudden surge damage to the foundation pit floor, shortening the auxiliary dewatering operation cycle, reducing the space occupied by equipment in the foundation pit and the need for repeated adjustments to procedures, and improving the overall construction efficiency.

[0074] As another implementation, after the mounting frame 100 is fixed to the foundation pit slope 20 by anchor bolts, the tilt angle of the support frame 200 can be adjusted by an appropriate distance measuring method, so that its bottom end is stably abutted against the soil to be excavated 10 in a suitable proportion, ensuring that the positional deviation between the center of the rotary drilling mechanism 300 and the center of the predetermined auxiliary dewatering area is within a controllable range; when the lifting drive unit 310 is started, a suitable matching relationship between the sinking speed and the rotation speed of the rotary drilling drive component 341 is set, so that the first rotary cutting protrusion 344 and the second rotary cutting protrusion 346 on the cutterhead body 343 can directly rotary dig to form a temporary drainage well 30 without a well wall pipe, while simultaneously removing larger particles. The mud clumps are effectively broken up; the inlet end of the mud suction hose 460 is evenly fixed by the first limiting holes 501 on multiple first ear plates 500, and the inlet end of the groundwater suction hose 470 is evenly fixed by the second limiting holes 601 on multiple second ear plates 600, ensuring that the two inlet ends maintain a stable following state within the maximum stroke; after the dewatering mechanism 400 is activated, the first pump body 410 and the second pump body 420 can be linked with the water level monitoring device to synchronously adjust the stroke of the lifting drive unit 310 according to the descent depth of the excavation face, so that the rotary drilling unit 340 always leads the current excavation face by a preset depth of 2.0m to 3.5m. In this embodiment, different fixing methods, speed matching relationships, number of ear plate arrangements, and advance depth adjustment strategies further expand the applicability of this method to different soil conditions and foundation pit depths. During implementation, after the bottom of the support frame 200 provides stable support, the lifting drive unit 310 drives the connecting component 320 to move downward. The rotary drilling unit 340 rotates and cuts simultaneously with the mud block crushing. The filter unit 330 completes mud blocking and groundwater diversion in real time. The liquid inlet of the dewatering mechanism 400 moves downward synchronously with the first ear plate 500 and the second ear plate 600. The first pump body 410 and the second pump body 420 continuously pump at a fixed position. The lifting drive unit 310 adjusts its stroke in real time according to the excavation depth, thereby solving the technical problems of long well completion cycle, easy blockage, lag behind excavation, and high risk of sudden surge in existing secondary wells. This achieves the beneficial effects of improving construction efficiency, ensuring foundation pit safety, and reducing overall costs.

[0075] The above description is merely an embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A dewatering auxiliary device for foundation pit excavation, used for auxiliary dewatering of local deep confined water or complex aquifers within the foundation pit, based on the initial dewatering through primary wells, characterized in that, The foundation pit excavation auxiliary dewatering device includes: Mounting frame, which is fixed to the slope of the foundation pit; The support frame is inclined vertically towards the slope, the top of the support frame is hinged to the end of the mounting frame away from the slope, and the bottom of the support frame abuts against the soil to be excavated in the foundation pit. A rotary drilling mechanism includes a lifting drive unit, a connecting assembly, a filtering unit, and a rotary drilling unit. The lifting drive unit is hinged to the end of the mounting frame away from the slope. The connecting assembly extends vertically and its upper end is fixedly connected to the lifting end of the lifting drive unit. The filtering unit is fixedly connected to the connecting assembly so that it moves vertically with the connecting assembly without rotating. The rotary drilling unit includes a rotary drilling drive component and a cutterhead assembly. The rotary drilling drive component is installed at the lower end of the connecting assembly. The cutterhead assembly is located below the filtering unit and is vertically spaced by a predetermined distance from the filtering unit. The rotary drilling drive component drives the cutterhead assembly to rotate around a vertical axis. The precipitation mechanism includes a first pump body, a second pump body, a first hose reel, a second hose reel, a mud suction hose, and a groundwater suction hose. The first pump body and the second pump body are fixedly mounted on a support frame. The first hose reel and the second hose reel are rotatably mounted on the support frame. The mud suction hose is wound around the first hose reel, with its inlet end extending into the filter section and its outlet end connected to the inlet end of the first pump body. The groundwater suction hose is wound around the second hose reel, with its inlet end extending into the filter section and its outlet end connected to the inlet end of the second pump body. The filter section includes a first filter ring and a second filter ring arranged coaxially. The first filter ring is sleeved outside the second filter ring, and a mud suction chamber is formed between the first filter ring and the second filter ring. A groundwater suction chamber is formed on the inner circumference of the second filter ring. The mud suction chamber and the groundwater suction chamber are connected through the second filter ring. The inlet end of the mud suction hose is engaged with a first limiting hole on a first ear plate on the inner wall of the first filter ring, and the inlet end of the groundwater suction hose is engaged with a second limiting hole on a second ear plate on the inner wall of the second filter ring. Both the first limiting hole and the second limiting hole extend vertically so that the two inlet ends move vertically synchronously with the filter section. The lifting drive unit drives the connecting assembly to move vertically up and down, so that the filtering unit and the rotary drilling unit move up and down synchronously. The cutterhead assembly directly drills in the soil to be excavated to form a temporary drainage well without a well wall pipe. The filtering unit moves down synchronously with the rotary drilling unit. During the rotary drilling process, the mud entering the temporary drainage well is filtered in stages by the first filter ring and the second filter ring, allowing groundwater to pass through the second filter ring and enter the groundwater suction chamber. The first pump body is used to pump out the mud in the mud suction chamber through the mud suction hose, and the second pump body is used to pump out the groundwater in the groundwater suction chamber through the groundwater suction hose. Furthermore, during the excavation of the foundation pit, the stroke of the lifting drive unit is adjusted synchronously according to the descent depth of the excavation face, so that the rotary drilling unit always stays ahead of the current excavation face by a preset depth, maintaining the effective dewatering depth of the temporary drainage well.

2. The foundation pit excavation auxiliary dewatering device as described in claim 1, characterized in that, The filtration unit further includes a mounting base plate, which is fixedly connected to the outer wall of the connecting assembly. The first filter ring extends along the periphery of the mounting base plate and is fixedly connected to the mounting base plate. The second filter ring is coaxially arranged with the first filter ring. The groundwater suction chamber is formed between the second filter ring and the connecting assembly.

3. The foundation pit excavation auxiliary dewatering device as described in claim 2, characterized in that, The cutter head assembly is coaxially arranged with the first filter ring. The cutter head assembly is located below the mounting base plate and is vertically spaced from the mounting base plate by a preset distance. The output end of the rotary drilling drive is connected to the cutter head assembly.

4. The foundation pit excavation auxiliary dewatering device as described in claim 3, characterized in that, The cutterhead assembly includes a cutterhead body, a plurality of first rotary cutting protrusions, and a connecting shaft. The cutterhead body is coaxially arranged with the first filter ring. The orthographic projection area of ​​the first filter ring on the cutterhead body is smaller than the orthographic projection area of ​​the cutterhead body. The cutterhead body is connected to the output end of the rotary drilling drive through the connecting shaft. The plurality of first rotary cutting protrusions are spaced apart at the bottom end of the cutterhead body and all extend vertically.

5. The foundation pit excavation auxiliary dewatering device as described in claim 4, characterized in that, The cutter head assembly also includes a plurality of second rotary cutting protrusions, which extend radially along the cutter head body and are spaced apart along the periphery of the cutter head body and are fixedly connected to the cutter head body.

6. The foundation pit excavation auxiliary dewatering device as described in claim 3, characterized in that, The connecting assembly includes a connector and an annular cage. The annular cage is fitted onto the outer wall of the connector and fixedly connected to the connector. The connecting end of the rotary drilling drive is installed at the bottom end of the connector through the annular cage. The mounting base plate is installed on the outer wall of the connector and is located near the lower end of the connector.

7. The foundation pit excavation auxiliary dewatering device as described in any one of claims 1 to 6, characterized in that, The precipitation mechanism also includes an installation rod, which is detachably mounted on the support frame. The first hose reel and the second hose reel are respectively rotatably sleeved on the installation rod. The first pump body and the second pump body are installed at intervals at one end of the support frame away from the slope.

8. The foundation pit excavation auxiliary dewatering device as described in any one of claims 1 to 6, characterized in that, The first ear plate is welded and fixed to the inner wall of the first filter ring, and the second ear plate is fixed to the inner wall of the second filter ring by bolts. The inlet end of the mud suction hose and the inlet end of the groundwater suction hose are respectively provided with clamping connectors to be clamped in the first limiting hole and the second limiting hole respectively.

9. The foundation pit excavation auxiliary dewatering device as described in any one of claims 1 to 6, characterized in that, The vertical distance between the cutter head assembly and the filter section is 300mm to 800mm, and the rotary drilling section is 2.0m to 3.5m ahead of the current excavation face.

10. A method for assisted dewatering during foundation pit excavation, characterized in that, The foundation pit excavation auxiliary dewatering device as described in any one of claims 1 to 9, wherein the foundation pit excavation auxiliary dewatering method comprises: The mounting frame is fixed to the slope of the foundation pit, the tilt angle of the support frame is adjusted so that the bottom end of the support frame abuts against the soil to be excavated, and the rotary drilling mechanism is positioned in the predetermined auxiliary dewatering area. The lifting drive unit is activated, which drives the connecting assembly to move the filter unit and the rotary drilling unit downwards vertically in sync. The rotary drilling drive unit drives the cutterhead assembly to rotate, directly rotary drilling in the soil to be excavated to form a temporary drainage well without a well wall pipe. At the same time, the filter unit moves downwards synchronously with the rotary drilling unit and does not rotate. During the rotary drilling process, the mud entering the well is filtered in stages by the first filter ring and the second filter ring, allowing the groundwater to pass through the second filter ring and enter the groundwater suction chamber. When the dewatering mechanism is activated, the first hose reel and the second hose reel rotate to wind up and unwind the hoses, causing the two inlet ends to move down synchronously with the filter section. The first pump body extracts the mud from the mud suction chamber through the mud suction hose, and the second pump body extracts the groundwater from the groundwater suction chamber through the groundwater suction hose, so as to carry out auxiliary dewatering for local deep confined water or complex aquifers on the basis of the initial dewatering of the first-stage well. During the excavation of the foundation pit, the stroke of the lifting drive unit is adjusted synchronously according to the descent depth of the excavation face, so that the rotary drilling unit always stays ahead of the current excavation face preset depth, and maintains the effective dewatering depth of the temporary drainage well.

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